Engine Wire Harness and HEI conversion

[ACK]

I'm making the jump to a HEI distributor. I've been reading up and want to confirm I did my homework right. Attached is a pic of my wiring harness ('64 C10 with 4.1L) and here's my questions:

1. Did I identify the wires on the harness correctly?
2. Can I replace the white resistor wire with multi-strand heat/oil/gas resistant 12-gauge and run it straight to the HEI as my ignition power wire?
3. Any reason to keep the dark blue wire?

As a side, my resistor wire runs straight from the harness to the starter. Thanks!

[tincan1966]

The only correction is the dk blue wire should be the oil sender with light in dash. With gauge used a copper hard line direct to the gauge.

And yes remove the white wire from the engine side of the connector, and install new replacement end on new stranded wire and run direct to HEI. You can also remove the yellow wire running from the "R" post on the starter to the + side of the original coil.

Hope this helps

[Sharps40]

When I put HEI on my 6 I...

Removed the wire from starter to coil and tossed that wire out.

Removed the resistance wire from the bulkhead connector to the same terminal of the coil as the starter wire and tossed it out.

Removed the coil and points dizzy and tossed em out.

Installed the HEI Dizzy with Coil in cap.

Ran a 12g new wire with soldered terminals from the resistance wire socket of the bulkhead connector to the proper terminal on the new hei dizzy.

Timed it, started it and running great ever sense....

(I did not use the ignition unfused terminals of the fuze box to power the dizzy...figured to go direct from the bulkhead connector and rewrapped the wires so it all looks like factory wireing harness.)

I wrote it all up with pics in the John Lee Jr thread. Spect it'll be similar for a v8.

[ACK]

Thanks Tincan1966 and Sharps40. The PO put in an aftermarket oil pressure gauge and I completely missed the dumby light wire on the wiring diagram. Can't wait to get the HEI installed, just waiting on the new cap to arrive.

[tincan1966]

I almost forgot to mention. You may want to increase your plug gap to .045" and even step up one heat range. You'll be able to run more advance and have alot more tunability with the carb, too.
It's about the most cost-effective improvement you can make(so long as you buy a decent distributor, LOL)

[Sharps40]

Luck to ya. I gapped my plugs at 45 thou. For the I6, Mr. Langdon at Stovebolts recommends 60 thou.

I was amazed at how much initial timing can be run with an HEI. My 230 was 4 degrees advance with points and with the HEI I run 18 degrees advance (its all in at 35 or so degrees at 3000 RPM).

Mileage was up a bit before I put in the two barrel but the big change was instant start (hot or cold) and idle smooth enough to amaze me and a lot more responsive to inputs from the gas pedal.

[Druman]

i just took the yellow wire from the starter and black wire from the ignition tide them together into a painless power pigtail from autozone. fired right up.

[tincan1966]

The thing to remember here:

The yellow wire from the starter "R" terminal only provides 12V+ while cranking.

The original wire from the bulkhead connector on the passenger side behind engine, (as pictured above) will have a resistance wire leading to the original coil.(normally white) This will provide lower than 12V+ voltage while running. Unless this wire is replaced with regular wire and full voltage is recieved at the HEI during operation, damage to the module and coil could happen, or at the least they will live a shorter life.

Low voltage and poor grounding are the too most common factors in electrical component failure.

[Druman]

Originally Posted by tincan1966

The thing to remember here:

The yellow wire from the starter "R" terminal only provides 12V+ while cranking.

The original wire from the bulkhead connector on the passenger side behind engine, (as pictured above) will have a resistance wire leading to the original coil.(normally white) This will provide lower than 12V+ voltage while running. Unless this wire is replaced with regular wire and full voltage is recieved at the HEI during operation, damage to the module and coil could happen, or at the least they will live a shorter life.

Low voltage and poor grounding are the too most common factors in electrical component failure.

Scratch what I said; I like everything that he said. I received a 12V signal with the key on and ran with it I did not think to ck the volt reading while it was running. Thanks for the heads up. And yes my wire is white originally just black from years of engine life.

[bmur66]

Thanks guys. This thread is also helping me make some sense out of the wiring when switching to a mini starter with HEI. I might have a few questions soon.

[Sharps40]

You can ignore the starter for the HEI. The wire from the starter is not needed on an HEI. Just hook the HEI to either the bulkhead (where you removed the points resister wire-this comes direct from ignition switch) or hook the hei to the fuze box at an empty "ignition unfused" port. Either way, try to use 12 g wire for the hei. Its a chore to hook such a large wire to the bulkhead connection but it can be done with a new brass connector crimped and carefully soldered to the wire.

In either event, throw away the starter to points coil wire and throw away the bulkhead to points coil resister wire.

Wire the mini starter per instructions that come with it. It may show a wire to the coil but that would be for a points set up not for an hei.

Anyone else, chime in if I got it wrong.

[Sharps40]

For HEI Swap on an I6 start reading at post 117 of the link below.


Make sure you install an internally regulated Delco 10SI or 12SI alternator first....(install of a 12SI is in there too a page or three before the HEI swap) so you don't get voltage spikes that fry your new HEI. The old externally regulated alternators often are not stable enough power supplies for an HEI conversion.

http://67-72chevytrucks.com/vboard/s...d.php?t=571916

[Sharps40]

Theres lots of extra info in there further on as I tuned the ignition and a new weber carb. I eventually settled on 18 degrees of static advance per Mr. Langdons recommendation for using an HEI on a I6...some verification showed I had about 36 degrees total mechanical advance at 3000 rpm. The thread also tells how to check this amount of advance using the factory timeing tab which only reads to 12 or so degrees of advance.

Start conservative, about 10 degrees of advance and then tune up or down from there for best performance on your engine and carb/exhaust combo. Mine is all stock fresh rebuild except for the Weber 2 barrel.

[gulfcoast66]

Great Info!!!
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